#include <stdio.h>
int f(int a)
{
	printf("calling f(%d)\n", a);
	if (a == 1) { return 1; }
	else { return a * f(a - 1); }
}

int main(int argc, char * argv[])
{
	printf("f(6) = %d\n", f(6));
	return 0;
}
